Yep, intermittent probs between 1030 this AM to 1516, a mix of error codes, 520, 522, 523, 524 - all CloudFlare issues since these are not regular HTTP error codes. They seems to suggest the problem may be over-long headers - has ARRSE changed any cookie policies lately?
Or should I run off and find my tinfoil hat in case our dear PM has decided to start his internet purge with that dangerous bunch at ARRSE?
I apologise for the problems today. I believe I know what the problem is, it only happens on Sundays (software RAID resync cron job for those interested in these things) and I think it can be fixed with a small amount of money, and probably a short outage to get our hosts to upgrade the database server.